Review of Functional Treatments for Modified Wood

Abstract

Wood modification is now widely recognized as offering enhanced properties of wood and overcoming issues such as dimensional instability and biodegradability which affect natural wood. Typical wood modification systems use chemical modification, impregnation modification or thermal modification, and these vary in the properties achieved. As control and understanding of the wood modification systems has progressed, further opportunities have arisen to add extra functionalities to the modified wood. These include UV stabilisation, fire retardancy, or enhanced suitability for paints and coatings. Thus, wood may become a multi-functional material through a series of modifications, treatments or reactions, to create a high-performance material with previously impossible properties. In this paper we review systems that combine the well-established wood modification procedures with secondary techniques or modifications to deliver emerging technologies with multi-functionality. The new applications targeted using this additional functionality are diverse and range from increased electrical conductivity, creation of sensors or responsive materials, improvement of wellbeing in the built environment, and enhanced fire and flame protection. We identified two parallel and connected themes: (1) the functionalisation of modified timber and (2) the modification of timber to provide (multi)-functionality. A wide range of nanotechnology concepts have been harnessed by this new generation of wood modifications and wood treatments. As this field is rapidly expanding, we also include within the review trends from current research in order to gauge the state of the art, and likely direction of travel of the industry.

Hybrid Approach for Wood Modification: Characterization and Evaluation of Weathering Resistance of Coatings on Acetylated Wood

“…Conventional wood modification systems use chemical treatments, impregnation or thermal modification, resulting in various intrinsic properties achieved. Innovative modification approaches focus on adding some extra functionalities, such as UV stabilisation, fire retardancy or enhanced suitability for paints and coatings [50]. Although each modification process improves certain material properties on its own, the positive effect can be multiplied by merging two or more modification solutions.…”

Surface Hydrophobization of Block-Shaped Wood with Rapid Benzylation

“…A thin sample (approximately 0.1 mm) was cut out from near the surface, shredded, and then used for NMR measurement. The samples were placed in a 4 mm ZrO 2 rotor spun at 15 kHz within a temperature range of 24-26 • C. 1 H MAS NMR spectra were collected with a 2.9 µs π/2 pulse at 399.87 MHz for the 1 H nuclei and were collected with a 40 ms acquisition period over a 30.5 kHz spectral width in 16 transients, with a 3 s recycle delay. 13 C MAS NMR spectra were collected with a 2.6 µs π/2 pulse at 100.56 MHz for the 13 C nuclei and a 40 ms acquisition period over a 30.5 kHz spectral width.…”

“…However, wood has various problems such as low dimensional stability, perishability, and flammability, which limit the industrial use of wood. To overcome these problems, various modifications have been studied and some results have been achieved [1][2][3]. However, many issues remain, such as the complexity of processing and the environment impact of the process.…”

A Superhydrophobic, Antibacterial, and Durable Surface of Poplar Wood

“…As a natural material, wood is one of the most important materials for structural construction, furniture, energy, and aerospace industries [ 1 ]. However, the negative characteristics of wood, such as water absorption, UV degradation, and poor resistance to microbial action, have limited the application of wood [ 2 , 3 ].…”